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A323705 Odd primes p such that ((p+1)/2)^(p-1) == 1 (mod p^2). 0
1897121, 52368101, 126233057 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The corresponding sequence when (p+1) in the congruence is replaced with (p-1) seems to be A125854.
a(4) > 4262937421 if it exists.
LINKS
MATHEMATICA
Select[Prime[Range[718*10^4]], PowerMod[(#+1)/2, #-1, #^2]==1&] (* Harvey P. Dale, May 14 2021 *)
PROG
(PARI) forprime(p=3, , my(x=(p+1)/2); if(Mod(x, p^2)^(p-1)==1, print1(p, ", ")))
CROSSREFS
Sequence in context: A032597 A203794 A204672 * A249318 A194620 A182360
KEYWORD
nonn,hard,bref,more
AUTHOR
Felix Fröhlich, Jan 24 2019
STATUS
approved

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Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)